Field of the Invention
The present invention relates to apparatus for use in the repair of machines and is primarily but not exclusively concerned with apparatus for supporting and/or the transportation of and/or the repair of rotors in turbine machines, in particular rotors from electricity generating steam turbines.
Turbine rotors are subjected to wear and damage during use and the occurrence of damage, for example the breaking of one or more turbine blades, may necessitate immediate repair.
Irrespective of any damage requiring immediate repair, because of the wear to which the blades are subjected during use, after a period of time it will be necessary for some renovation to be carried out.
It is usual when carrying out repair or renovation to dismantle the turbine, remove the rotor from the turbine and subsequently remove the blades from the rotor. The removal of the blades and the rotor itself can cause considerable damage to the blade and require eventual replacement thereof.
On re-assembly, the subsequent re-alignment of the blades in a rotor with respect to each other and replacement of lacing wires and shrouds is also time consuming which not only leads to considerable expense but prolongs the out-of-use time of the turbine.
Applicant has already proposed many different methods of repair enabling repair of turbine blades to be carried out with turbine blades in situ on the rotor, i.e. without their removal therefrom.
It has been found that it is extremely difficult to carry out some repair steps whilst the blades are in situ since the accuracy required when machining the blades after repair, and re-aligning the blades relative not only to each other but to the rotor, is acute.